Parenteral administration set and air inlet closure structure for use therein



April 1955 N. M. NESSET ET AL PARENTERAL ADMINISTRATION SET AND AIR INLET CLOSURE STRUCTURE FOR USE THEREIN Filed Dec. 18, 1952 I N V EN TOR. .Alnurz'ce M Wen-e: Cyrus 19. 131-02774):

United States Patent PARENTERAL ADMINISTRATION SET AND AIR INLET CLOSURE STRUCTURE FOR USE 'IHEREN Nani-ice M. Nesset, Palatine, and Cyrus R. Brennan, Evanston, 111., assignors to Baxter Laboratories, Inc, Morton Grove, 11]., a corporation of Delaware Application December 18, 1952, Serial No. 326,702

1 Claim. (Cl. 128-214) This invention relates to a parenteral administration set and air inlet closure structure for use therein. This invention can be employed with particular advantage in the parenteral administration of intravenous liquids such as saline solutions, glucose solutions, invert sugar solutions, etc.

One or" the problems associated with the intravenous administration of liquids is due to the difliculty of inserting the administration needle in the vein. It is the present practice to tentatively insert the needle, and then to flex the hose communicating with the needle as a test for the proper positioning. If the end of the needle is within the vein in the desired position, blood will be drawn back into the hose, which is usually formed of transparent plastic so that the blood can be seen. However, this method of first inserting the needle and then checking to see whether it is correctly positioned frequently requires a number of attempts to insert the needle in the vein, which is both vexatious to the operator and uncomfortable for the patient.

it is therefore a general object of this invention to provide a parenteral administration set which substantially overcomes the above problem, and permits the correct positioning of the needle to be determined instantaneously as it is inserted, and without requiring the step of flexing the hose to see whether the needle is in cornrnunication with the vein. Further objects and advantages will appear as the specification proceeds.

This invention is shown in an illustrative embodiment in the accompanying drawing, in which- Fig. 1 is a plan view of a parenteral administration set embodying the principles of this invention; Fig. 2 is a detail perspective view of the closure plug and air inlet tube structure of the container shown in Fig. 1; Fig. 3 is a perspective view of the air inlet tube, showing the removable cap seated on the end of a tube; and Fig. 4 l

is a perspective view of the flexible cap member which is preferably employed in this invention, as illustrated in the preceding figures.

Looking first mainly at Fig. 1, there is shown an apparatus for the administration of an intravenous liquid including a supply container or bottle A and a conduit means or assembly B, providing a communicating passage from container A to the point of the administration of the liquid, which, for example, could be at C.

in the specific illustration given, in order to provide for the supporting of container A in an inverted position, as shown, it is provided with a recessed ring having a support bail 11 pivotally connected thereto. Container A is also provided with a neck portion 12 enclosing an open month which is covered by a closure assembly 13 having a retainer ring 14 which holds plug or stopper 15 in place.

Stopper 15 can be constructed of a resilient flexible material such as soft rubber, and is provided with an air inlet opening 16 and a fluid outlet opening 17, as seen more clearly in Fig. 2. As shown in Fig. l, a hollow plug-in connection 18 is inserted in opening 17 with its lower end secured to a flexible substantially transparent hose 19. The other end of hose 19 is connected through adaptor 29 to administration needle 21. Hose 19 is also provided with an adjustable control clamp 22 which, in the illustration given, is formed of malleable metal.

At the start of the administration as indicated in Fig. 1, the intravenous fluid will partially fill container A, for example, to the level indicated by the dotted line 23, thereby leaving an air space 24 above the liquid. With "ice the container supported in a mouth-downward position as shown, the air space 24, of course, will be at the top and the intravenous fluid will be in direct communication with fluid outlet 17. In order to prevent a vacuum from building up in air space 24 and thus stopping the outflow of liquid through opening 17, it is necessary to provide an air inlet opening, such as opening 16. If desired, a glass tube can be extended from opening 16 to a point Within the air space above the liquid level when the container is inverted. Instead of this conventional air tube,

there can also be provided an air inlet tube of the type which is illustrated herein.

In the illustration given, air inlet tube 25 is shown with its inner end portion inserted into opening 16. Air, inlet tube 25 functions to admit bubbles of air to container A at a controlled rate, while at the same time preventing the escape of liquid through the air inlet tube.

In the illustration given, air inlet tube 25, as seen more clearly in Fig. 2, provides an air inlet passage ex-. tending through the body thereof consisting of an outer chamber 25a containing a body 31 and communicating with a restricted passage portion 25b. inwardly. beyond restricted portion 25b there is provided a chamber 25c. it is inherent in the operation of this structure that air will pass inwardly through chamber 25 and then through restricted portion 25b to collect in chamber 250. Discrete bubbles of air, as indicated in Fig. 1, will then be released from air collection chamber 250 at a rate directly proportlonal to the fluid outflow rate. The restriction 25b permits air to move in through the air inlet passage while at the same time preventing liquid from moving outwardly through the passage.

To realize the new results accomplished by this invention, it is necessary to provide the air inlet opening of container A with a removable closure, sealing the air inlet opening. For example, in the specific illustration given, cap 26 can be seated on the outer end portion of air inlet tube 25 in sealing relation therewith, as indicated in Fig. 3. Preferably, as shown, the closure structure for the air inlet opening, as cap 26, is removable and replaceable by sliding it axially with respect to tube 25.

A number of functional advantages have been found to result from the particular closure structure shown in the drawing. In the illustration given, cap 26 is composed of a flexible material such as soft rubber, and is provided with a laterally-extending thumb or pulltab 27. The other side of cap 26 is integrally connected to a flexible strap 23 which provides a flexing hinge for the remove]. and replacement of cap 26. The other end of strap 28 is integrally connected to ring 29 which encircles air inlet tube 25. Preferably, a shoulder or abutment 30 is provided between the outer end portion of tube 25 and its intermediate portion about which is placed ring 29, thereby preventing ring 29 from sliding toward the outer end of tube 25.

Operation At the start of the operation of the parenteral administration set disclosed herein, it is supported and assembled in the manner illustrated in Fig. 1, except that cap 25 is seated in the outer end of air inlet tube 25. At this point, clamp 22 is closed and hose 19 and needle 21 are filled with air. The pressure in air space 24 is at atmospheric pressure. Clamp 22 is then opened, while cap 26 remains seated on tube 25. This causes the intravenous liquid to flow downwardly through conduit 19 and out of needle 21, thereby removing the air from these elements and filling them with liquid. This flow will continue until a suiflcient vacuum is created in air space 24 to balance the hydrostatic head of the liquid. The set is then ready for the insertion of needle 21 in the vein of the patient. Due to the reduced pressure within air space 24, as soon as needle 21 penetrates a vein, the relatively greater pressure within the vein will immediately cause blood to flow upwardly through needle 21 and into the lower portion of hose 19, thereby becoming visible to the operator and providing a positive indication that the needle is in contact with the vein. Cap 26 can then be removed and the liquid administered to the patient by the inflow of air through opening 16 and the outflow of liquid through opening 17. The administration can be interrupted at any point, if desired, and cap 2.6 will be readily at hand for re lacement on the outer end of tube 25. It'rnay be desire to temporarily remove the needle from the patient, in which case the process described above can be repeated for the next insertion of thezneedle. It will be apparent that the method of operation described lends itself best to the administration of intravenous liquids which have a difi'erent physical appearance than whole blood, so that the appearance of blood in the conduit can'readily be detected.

While in the foregoing specification a specific embodiment of this invention has been described in detail, it will be apparent to those skilled in the art that many of the details set forth can be varied widely without departing from the broad idea of the invention.

We claim:

In a parenteral administration set, a mouth-equipped container supported in a mouth-downward position, said container being partially filled with an intravenous liquid having an air space thereabove, said liquid having a different physical appearance than whole blood and said ir space being at substantially atmospheric pressure, a closure for said container mouth providing an air inlet opening for admitting air in said air space and a liquid outlet opening for discharging said intravenous liquid, at downwardly-extending substantially transparent conduit communicating with said liquid outlet opening,

equipped at its lower end with an injection needle, and intermediately with a releasable clamp, said conduit and needle being filled with air and said clamp being in closed position to prevent liquid from leaving said container, and means closing said-air inlet opening including a removable and replaceable closure, whereby upon opening said clamp with said closure in place the outflow of fluid will flush out said conduit and needle and at the same time reduce the pressure in said air space below atmospheric pressure, and, after said outflow has terminated, the insertion of said needle into a vein will immediately be evidenced by the appearance of blood in the lower portion of said conduit, thereafter said liquid can be administered by removing said closure and terminated by replacing said. closure.

References Cited in the file of this patent UNITED STATES PATENTS 

